This invention relates generally to apparatus for burying pipe and more particularly to apparatus for traversing marshes, streams or other bodies of water to bury a pipe within the ground under that body of water.
In order to bury a pipeline in the ground under a body of water, it had heretofore been a practice to cut a ditch in the ground under the water, insert the pipe in the ditch and thereafter fill the ditch. This three-step technique is no longer acceptable in many areas due to environmental concerns, e.g., digging the ditch and then thereafter filling it frequently resulted in death or injury to fish or other wildlife in the water.
Another technique used heretofore for burying pipelines under water is through the use of a sled-type device having a plow blade mounted to project downward thereunder. The sled is arranged to be towed across the ground under the water so that the downwardly projecting blade cuts a furrow in the ground. The pipe is connected via a chain or cable to the blade so that it is pulled through the furrow as the furrow is cut. This technique, while obviating some of the ecological problems of the prior art three-step process, nevertheless leaves much to be desired. In this connection, it is difficult to drag the pipe through the furrow (which when cut is somewhat narrow to minimize the disturbance of the soil as the blade cuts it). In addition, the pipe is susceptible to damage or scoring as it is dragged through the furrow. Such damage and/or scoring can be caused by impacting buried obstacles, e.g., rocks. Moreover, the prior art sled is quite large in size and cumbersome to maneuver and also is of limited application, inasmuch as its blade height is fixed. Thus, the depth of the furrow which is cut by the blade cannot be adjusted to accommodate various terrain. Moreover, a further limitation on the usefulness of the prior art sled is that it requires excavation of the soil down to the location of the pipe to uncouple the pipe from the sled so that the sled can be taken away after the pipe is in place.